[Bug: 21.4.22] Sporadic crash entering a group with Gnus

[Stephen J. Turnbull]

Aidan Kehoe writes:

 >  > If --without-assertions is *necessary*, I would guess that the same
 >  > error is normally caught by an assertion somewhere.
 > 
 > It means a bug in the semantics of the assertion, then. 

You're assuming that XEmacs gets past the assertion.  I mean that the
assertion crashes XEmacs before we get to the unrecognized byte code
abort.

I do see very occasional assertions (various ones), but they always
correspond to unresolved bugs, what I can get from the debugger is
invariably unhelpful, and I've not be able to reproduce.  So I've not
done much about them.

However this time we seem to have a specific issue (byte-compiling the
gnus-summary-highlight expression), maybe we can reproduce.